1. Field of the Invention
The present invention relates generally to air bearing surface designs for sliders including magnetic heads for hard disk drives, and more particularly to a slider air bearing surface that is designed to adjust its fly height above a disk surface in response to protrusion of portions of the air bearing surface caused by heat generated within the magnetic head.
2. Description of the Prior Art
As is well known to those skilled in the art, standard hard disk drives include magnetic media disks that are rotatably mounted upon a motorized spindle. A magnetic head slider is mounted upon an actuator arm such that the slider flies above the surface of the disk on the moving air film associated with the rotating disk surface. The moving air film is generally referred to as an air bearing, and the flying height of the slider is generally referred to as the air bearing gap.
In the continual quest for higher areal data recording densities of the hard disk drive, it is important that the slider air bearing gap be reduced, such that smaller magnetic data bits can be written to and read from the magnetic media at ever increasing speeds. As is well known to those skilled in the art, at high data writing rates significant heat is created within the magnetic head components and within the rearward portions of the slider located proximate the magnetic head components. The heat causes material expansion within the magnetic head and slider, which causes portions of the magnetic head and slider to protrude outwardly from their nominal locations towards the rotating magnetic media disk. This protrusion substantially reduces the air bearing gap at the protrusion location and increases the likelihood that unwanted physical contact will occur between the rotating disk and the protruding portions of the slider, thereby causing damage to the disk surface or to the protruding magnetic head components of the slider.
Prior art efforts to control the protrusion problem have focused on the fabrication of heat sink structures within the magnetic head components to draw the unwanted heat away from the magnetic head, thereby reducing the protrusion. The present invention utilizes a different strategy by making the slider flying characteristics more sensitive to the protrusion, such that the slider fly height is increased based upon the degree of protrusion and the air bearing gap is not significantly reduced by the protrusion.